Telephone-transmitter.



R. ROYAL.

TELEPHONE TRANSMITTER.

APPLICATION FILED AUG. 11, 1911.

1 ,OOfiS'Y. Patented Oct. 8, 1912.

PATENT ROSCOE ROYAL, OF CHICAGO, ILLILT OIS, ASSIGNOR T CORWIN TELEPHONE MANU- FACTUBING COMPANY, OF CHICAGO, ILLINOIS, A CORPORATION OF ILLINOIS.

TELEPHONE-TRANSMITTER.

Specification of Letters Patent.

- Patented Oct. 8, 1912.

' To an whom it may concern:

Be it known that I, Roscoe ROYAL citizen of the United States, residing at (lhicago, in the county of Cookand State of Illinois, have invented a certain new and useful Improvement in Telephone-Transmitters, of which the following is a full, clear, concise,

and exact description, reference being had tuation in transmitted telephonic currents so that the frequency of such transmitted currents is reduced whereby such currents are adapted to be transmitted over longer distances,the transmitter of my invention thus being. of particular service for long distance telephony.v

'My invention may generally be described as comprising a transmitter including a stationary cup having a flexible'closure, trans mitter electrodes presented to the interior of the on one of these electrodes being carried by t e flexible closure so as to be movable, comminuted current conducting material within the cup and interposed-between the electrodes for electrically connecting the same in the transmitter circuit, a speaking diaphragm and a medium for conducting vibrations interposed between the electrode carried by the flexible closure and a portion of the speaking diaphragm laterally disposed with respect to said electrode. I n the preferred embodiment of my invention I employ a spring structure mechanically constituting a continuation of sald medium and serving to press said medium into engagement with the. diaphragm.

I will explain my invention more fullyby reference to the accompanying drawing showing the preferred embodiment thereof and in which like parts are indicated by similar characters of reference throughout the different figures.

A month piece a is. screwed within a mounting late 6 for the various parts of the transmitter, which mounting plate may also support a housing, not shown, for transmitter parts located to the rear of said mounting plate. A bridge 0 is secured to a flange d projecting rearwardly from the mounting plate I). A cup 0 is provided with a rearwardly extending stem 7 that passes through an aperture in the bridge and which is secured in position by means of a clamping screw 9 so that the cup is normally stationary, though adjustable in position. The cup is provided with a flexible closure 72., preferably made in the form. of a disk of mica. This closure is secured in position upon thecup by means of the flange clamping ring 2. The flexible closure it carries a button thathas a facing of carbon is, preferably in the form of a carbon disk. The base of the cup is provided with a facing of carbon Z preferably also in the form of a carbon disk. The elements is and Z constitute electrodes of the transmitter and are preferably included in circuit by means of the conductors 1n and n, independently of the speaking diaphragm that is later referred to. Comminuted conducting material, preferably in the form of carbon, is located within the cup so as to bein contact with the electrodes is and Z, this. ranular element being indicated at 0. s the function of the element 0 is well understood I will not describe the same. A speaking diaphragm p is held, at its periphery, against the rear of the mounting plate I) by means of a spring structure that is preferably formed in two symmetrically related bent strip springs q, these springs exerting pressure upon the speaking diaphragm through the intermediation of buttons or prongs r of insulating material, under the assumption that the speaking diaphragm is not to be included in circuit. These buttons or prongs r engage portions of the speaking diaphragm p that are laterally displaced with respect to the movable electrode is that is carried by the cup closure h. A medium for transferring vibrations from the speaking diaphragm to the movable electrode 7; desirably. resides in a substantially rigid =yoke ethat is preferably integrally formed 'with' the springs g. This yoke is attached at its center to the button that is in fixed relation with the electrode is, current finding 'assage by way of the elements 3 and q to t e conductor n. The vibrations imyparted to the speaking diaphragm by a speakers voice have greatest amplitude iio - at the center of the diaphragimfthat point trode k sothat this electrode does not move in accordance with the greatest amplitudes of vibrations of the speaking diaphragm but does move in accordance with vibrations or" the speaking diaphragm where such vibrations are less prominent and are oflower frequency with the advantages that have hitherto been pointed out.

Having thus described my invention I claim as new and desire to secure by Letters Patent the following 1. A telephone transmitter including a stationary cup having a flexible closure; transmitter electrodes presented to the interior of the cup, one of these electrodes being carried by the flexible closure so as to be movable; comminuted current conducting material within the cupand interposed between the electrodes for electrically connecting the same in the transmitter circuit; a speaking diaphragm; and a medium for conducting vibrations interposed between the electrode carried by the flexible closure and a portion of the speaking diaphragm laterally dis posed with respect to said electrode; such interposition of said. medium between the electrode carried by the flexible closure and the speaking diaphragm being independent of the aforesaid stationary cup; and a spring structure for pressing said medium into engagement with the speaking diaphragm where it engages the same.

2. A telephone transmitter including a stationary cup having a flexible closure; transmitter electrodes presented to the interior-of the cup, one of these electrodes being carried by the flexible closure so as to movable; comminuted current conducting material within the cup and interposed be tween the electrodes for electrically connecting the same in the transmitter circuit; a

speaking diaphragm; and a medium for conducting vibrations interposed between the e ectrode carried "-by the flexible closure "and a portion of the speaking diaphragm laterally disposed with respect toQsaid electrode such interposition 0f said" medium between the electrode carried by the flexible closure and the speaking diaphragm being independent of the aforesaid stationary cup; and a spring structure mechani cally constituting a contmuatlon of said medium' and serving to press said medium into engagement with the diaphragm.

3. A telephone transmitter including a stationary cuphaving a flexible closure;

transmitter electrodes presented to the 'interior of the cup, one ofqthese electrodes being carried by-the flexible closure so as. to be.

movable; -comminuted current conducting material within the cup and interposed between the electrodes for electrically connecting the same in the transmitter circuit;-a

spect to said electrode, such interposition of said medium between the electrode carried by the flexible closure and the speaking dia-' phragm being independent of the aforesaid 1 stationary cup; and a spring structure for pressing said medium-into engagement with the speaking diaphragm where it engages the same.

4. A telephone transmitter including a stationary cup having 'a flexible closure; transmitter electrodes presented to the interior of the cup, one of these electrodes-being carried by the flexible closure so as to be movable; comminuted current conducting material within the cup and interposed. between the electrodes for electrically connecting the same in the'transmitter circuit; a speaking diaphragm; and a substantially rigid medium for conducting vibrations interposed between the electrode carried by the flexible closure and a portion of the speak- I ing diaphragm laterally disposed with I'ebe spect to said electrode, such interposition of:

said medium'between the electrode carried by the flexible, closure and the speaking dia-.

phragm being independent of the aforesaid stationary cup; and a spring structure mechanically constituting a continuation of said medium -and serving to press said 1116-? dium into engagement with the diaphragm.

In witness whereof Ighereunto subscribe my name this 9th day of August A. 1).; 1911,

IROSCOE ROYAL.

Witnesses: 7 I

G. L. CRAGG, E. L. WHITE.

Ga nes of this patent may be obtained for five cents eacn,by addressing the Commissioner of new, 

